textproduct: Quad Cities

KEY MESSAGES

- Frost tonight mainly north of I-80 and in river valleys. Some localized freezing temps possible.

- There is a chance (20-40%) of diurnal showers Thursday and Friday. Not all areas will receive rainfall.

- Active pattern late weekend into next week, with best chances (40-70%) of showers/isolated thunderstorms Saturday night- Sunday.

SHORT TERM /THROUGH FRIDAY/

Issued at 220 PM CDT Wed May 6 2026

Early afternoon water vapor shows several shortwaves upstream in the cyclonic flow aloft tied to the large deep Hudson Bay trough. The first wave over northern IA is providing an increase in cloud cover with bases generally under 7kft along with the diurnal Cu gradually expanding. 18z surface observations already show northwest winds gusting up to 30kts, with very dry dewpoints in the low to mid 20s evident of deep mixing as shown on our 18z DVN sounding up to 770 mb. We also saw a -2.8C 850mb temp which is in the Top 25 coldest May soundings in our period of record per SPC climatology. Quite chilly for early May for sure!

Shortwave trough to swing east into WI/IL late afternoon and evening, with subsidence behind allowing for clouds to quickly clear after sunset. With such a dry boundary layer, there will be a period from 9pm to 4a where temperatures quickly drop into the middle 30s. NBM probabilities of temps<36 degrees tonight have increased and are now 60-90% north of I-80. Dewpoints to remain in the mid to upper 20s, which will still allow frost formation north of I-80. As a result in collaboration with neighboring offices, a frost advisory has been issued from 06-13z Thursday. Will have to watch upstream cloud trends across the Dakotas and MN this evening/tonight closely, as these may reach the northern border of the CWA early Thursday thereby keeping us a tad warmer. Conversely, if clouds completely clear out and winds go completely calm, we could even see freezing temps or even a few degrees lower, especially in rural and poor drainage areas.

Thursday...another shortwave in the northwest flow aloft to bring an increase in clouds early in the day. 12z CAMs, RAP soundings, and low level convergence progs show sufficient lift and moisture to bring scattered showers primarily south of Hwy 30 late morning/afternoon. Can't rule out an isolated rumble of thunder or two as well with 700-500mb theta-e lapse rates progged around 0. Have introduced slight/chance PoPs for this activity, but do want to mention not all areas will receive rain. Low level winds increase through the day and we should see another day of deep mixing/gusty winds near 30kts. Afternoon temps to be warmer but still below normal, with readings topping out in the low to mid 60s.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/

Issued at 220 PM CDT Wed May 6 2026

Northwesterly flow will continue to impact the region through early next week, accompanied by near-daily disturbances embedded in the flow.

After precipitation tapers off Thursday night, northwest flow will briefly return before another disturbance passes through late Friday. Limited moisture will keep precipitation widespread but light, with a 10-30% chance of QPF greater than 0.10 inches. Given elevated lapse rates into late afternoon, some thunderstorms may be possible (10-20%) with these showers.

Low-level southerly flow behind the departing system will advect warm air into the region into Saturday. As a result, temperatures Saturday are expected to rise to above-normal, which should be pleasant following the recent stretch of below-normal temperatures.

Sunday will bring the next precipitation chances as a wave translates through, accompanied by a surface low. Additional moisture advection ahead of this low, while weak, will provide moisture for another widespread but light precipitation event. Current QPF totals have a 20-50% chance of exceeding 0.10 inches. The area of highest accumulation continues to shift given uncertainty in the track of the low but remains along the southern half of the CWA. We will briefly return to northwest flow on Monday before another system moves through Tuesday, bringing the next chance (30-40%) for precipitation.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1215 AM CDT Thu May 7 2026

Winds will remain under 10 knots through sunrise. Un-hangared aircraft may have frost on them north of I-80. after 12z/07 a compact but strong upper level disturbance will generate isolated to scattered SHRA across eastern Iowa and northern Illinois with the highest concentration potentially between Highway 30 and I-80. Inverted V sounding to allow gusts into the mid 20 knots. TSRA potential is there after 18z/07 but coverage looks to be 10 percent at best and was not included in the 06z TAFs. Winds will diminish to under 10 knots after sunset.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Frost Advisory until 8 AM CDT this morning for IAZ040>042- 051>054-063>068. IL...Frost Advisory until 8 AM CDT this morning for ILZ001-002-007- 009-015>018. MO...None.